1. Field of the Invention
This invention relates generally to a protective apparatus for biomedical instrumentation, and more particularly relates to a protective system for a probe of a biomedical thermometer.
2. Description of Related Art
Medical thermometers are useful in the diagnosis of many diseases. Infrared (IR) thermometers have recently become popular because they require less time and less patient manipulation to obtain an accurate measurement of a patient's temperature than conventional mercury or electronic thermometers.
Infrared biomedical thermometers are typically used to measure a patient's temperature from the auditory canal and the tympanic membrane. Typically, such a temperature measurement can be performed in a matter of a few seconds or less. However, such thermometers are sensitive to changes in the optical characteristics of the probe which may be caused by contamination, vibrational shocks or other causes. In some cases, a sheath or probe cover is used which is transparent to IR energy. The cover is fastened in some way over the part of the instrument directed at the patient's tympanic membrane. Reuse of such a cover may result in contamination accumulating on the cover and because the cover lies in the optical path of the thermometer, such contamination may result in inaccurate temperature measurements as well as causing cross contamination from patient to patient. Disposing of the probe cover after each temperature measurement assists in avoiding both the accumulation of contamination in the optical path and patient cross contamination.
While such a cover assists in protecting this part of the instrument from contamination, the cover typically provides little or no shock protection, such as in the case when the instrument is dropped. In the case of a probe containing a waveguide which forms part of the optical path, damage suffered by the waveguide as a result of rough handling could result in inaccurate temperature measurements. Distortion or bending, no matter how slight, may cause a significant change in the optical path. Additionally, the introduction of dirt, condensation or other contaminants into the waveguide can adversely affect its performance. There may be occasions when a disposable cover is not present over the waveguide distal end, thus without some other type of protection, dirt or other contaminants could enter the waveguide and interfere with its subsequent operation.
It would be desirable to provide a protective system for the probe of a thermometer, which would protect the parts, such as the waveguide of the probe, and which would also prevent contamination of the waveguide and other parts which may make contact with patients or operators of the instrument. For an infrared thermometer, it would also be desirable for a probe cover portion of such a system to be transparent to infrared radiation. In addition, to avoid inadvertent contamination, it would be further desirable for the protective apparatus to include a means for sensing the existence and correct positioning of the probe cover. The present invention addresses these needs.